Metal Painting: The Complete Guide

When applying paint on metal using brush techniques, follow the below steps as your guide:

Step 1: Carryout out metal surface preparation process by following all the five steps surface preparation process to the latter.

Step 2: Prepare the paint by pouring the amount you need in another container filling it halfway.

Step 3: Dilute the paint to the required consistency depending on the coat thickness required. This is done by adding measured quantities of mineral spirit while stirring with a wooden stick. If the paint is too thick, more mineral spirit can be added or more paint if the mixture is over diluted.

Step 4: Dip the paint brush slightly into the paint; at the tip, the lightly apply the first paint coat on the metal surface. The paint can be applied from left to right or vice versa depending on the painter covering the entire metal surface.

Leave the first coat to dry for an hour before repeating the process for coat two and allowing to dry again. The number of coats applied will depending on the coat thickness that you need and the type of paint used. Once all the coats have been applied, allow the metal to dry for 24hours before moving to the final step.

Step 5: The drying metal can be touched by another object to check if it has completely dried. Once that is confirmed, you can spray lacquer seal coat over the painted metal and allow to dry. This helps protect the paint and also enhance the metal paint sheen. This finishing step is optional and can be skipped if it is not necessary.

There are different types of metal paints and each varies depending on specific ingredient used.

Oil-based Metal Paint

Oil-based metal paint consists of synthetic resins or plant-based oil, a solvent and pigments. It is mostly applied on metals which are mostly used outdoors like metal gates and fence, outdoor furniture, grills, etc. This is because it results into hard surfaces that can withstand harsh atmospheric conditions.

This paint gives a smooth, even finish, easy to clean surface and is durable when primer is applied before the paint. It is resistant to stains and marks and helps conceal surface imperfections on metals. Oil-based metal paints should be applied in well ventilations area because of the bad odour from the solvent when painting. They also take longer to dry, are flammable and costly than water-based paints.

Metal Paint Finishes

The type of metal finishing plays a role in determining the choice of oil paint as well as the finishing paint. Available finishing paint options play a role in durability and resistance and they are matte, glossy or semi-glossy.

Metals that will be exposed to harsh climatic conditions, more handling and cleaning can be applied with glossy finish paints. Less used, seldom cleaned and exposed metals can have matte finish while if you need flexibility, the semi-glossy finish works perfect.

Water-based Metal Paint.

This type of paint is made of acrylics, rubber composites, or vinyl and is also known as latex paint. Unlike oil-based paints, water-based paints are affordable, dry faster, do not fade, and do not have an unpleasant smell when applied. Water-based paint is popular because it is easy to clean after application and is a safer option.

This paint is not durable as oil-based paints and is therefore applied to indoor metals like bed rails, nightstands, etc. If applied directly to the metal without applying a primer, it leads to rusting of the metal. Primer application also improves water-based paint adhesiveness on metal surfaces.

Before applying a coat of paint on your metal, standard preparation steps should be followed for quality and durable outcome.

Surface Cleaning

This is done to remove any dust, dirt and grease. New metals are cleaned using mineral spirit to removes grease and immediately followed by rust-inhibit primer application. For painted but functional metals, dry cloth is used for cleaning and de- done by light sanding. Mineral spirit can be used in the end to ensure no grease is present and enhance adhesion. In some cases, mild detergents or recommended chemicals are used for cleaning persistent dirt.

Removal Of Loose Or Peeling Paints

Metal surfaces with loose or peeling old paints may require scraping, sanding or wire brushing by hand to remove them. This manual process is tedious and give poor outcome, therefore, power tool is used instead. The demerit of using power tool to clean is that it polishes the metal surface thus reducing its adhesive property.

Rust Removal

Rust wears out metals, thus should be removed before painting the metals. Wire brushing, sanding and cleaning then applying rust-inhibitive primer can convert rusted metal into paintable one.

Surface Repair

Some metals may have small holes or dents due to rust or any other causes. These can be remedied by applying epoxy-based composite directly into the hole or dent after thorough sanding and cleaning the area. If the hole/dent is big, fiberglass mesh together with epoxy filler are used to seal the hole.

Primer Application

Right primer application is the last and most important step in the metal surface preparation process. The type of primer to be used is determined by the type of metal, its functionality, exposure conditions, and desired appearance. Water-based primers should be avoided because they hasten rusting process due to moisture thus peeling the paint.

Recommended primers are rust-inhibitors, galvanized metal primers, and iron-oxide primers. While rust convertors prevent further rusting, galvanized primers improve paint adhesion on metals such as aluminum metals. Iron oxide and zinc chromate can be used on a variety of metals both indoors and outdoors.

Once the metal surface has been sufficiently prepared, painting can now occur in two steps process.

Step 1:

Inspect the metal you want to paint for any cracks, peeling or rust and move it to a work-area if portable. The work area should be well ventilated and covered with cloth and then prepare it using the above steps. Wear protective gears like dust coat and mask to protect you from dust and dirt.

Step 2:

Once the metal is prepped and the primer has dried, paint is applied as per the instructions.

Brush, rollers or spray paints can be used depending on the metal surface type. Several coats can be applied with each coat left to dry for a few hours before applying another one. Upon completion, the paint is left to dry overnight before spraying a sealer (optional) to protect the paint and give a nice sheen.